How about Machiavelli? He was perhaps the first person 1500 years to say sensible things about politics-as-they-are, rather than about politics-as-we-would-wish them. He had very substantial influence on the modern understanding of politics and government -- People in England and France who were building modern states seem to have read him closely.
In terms of philosophical method: His rhetorical style is to look around, give examples, and discuss counter-evidence -- rather than to reason forward from definitions. Perhaps relatedly, he was one of the few notable philosophers with real experience in the field he was writing about. He was a senior civil servant in Florence, with responsibility for military and diplomatic affairs. As a result, he was personally acquainted with many of the major figures in Italian politics of the time. He wasn't simply guessing how these things worked.
Perhaps relatedly, he was one of the few notable philosophers with real experience in the field he was writing about. He was a senior civil servant in Florence, with responsibility for military and diplomatic affairs. As a result, he was personally acquainted with many of the major figures in Italian politics of the time. He wasn't simply guessing how these things worked.
Which perhaps suggests it would be doing him a disservice to accuse him of being a philosopher. (Somewhat tongue in cheek.)
Since LessWrong is a major congregation point for certain philosophical ideas, and because people here tend to be more objective (in the sense of not being self-deluded) than elsewhere, I thought I'd ask people's views.
To be clear, by "Greatest Philosopher" I am referring not to the most correct philosopher in human history but the one who deserves the most credit for advancing human philosophy towards being more true.
Off the top of my head I would say that a prime candidate would be Hume- amongst other things he rejected the idea of a soul, realised to a much greater extent than his predecessors the limits of human knowledge, and opposed the idea that reason is somehow an objective force that can make priorities independent of emotions.
Aristotle deserves considerable credit relative for his time but doesn't make the list because although it wasn't his fault his ideas were dogmatically accepted and held back both science and philosophy later on.
Your thoughts?